Xplorer 360 image and backup method (recommended)

Original Xbox 360 drive:

Open the Xbox hard drive case and remove the hard drive

Connect to sata and power, boot to clean ms-dos, create hddss.bin backup of original hard drive using hddhackr -d

Create an image backup of partition 2 (Xbox 1 emulator, 256MB) using the File -> Backup Partition 2 in Xplorer360 xtreme 2 (you can also extract the files and insert them in partition 2 on the new drive later if you can see partition 2 in Xplorer360)

Flash new drive with 20 GB (for new 20 GB drive) or 120 GB (for new 120 GB drive) hddss.bin (created from step 2 above) using hddhackr -f and at the same time make sure when asked to create an undo firmware file. Ignore any timeout expired error. Shutdown to load the new firmware (reboot won't reload it)

Connect the new drive to Xbox 360 and format using System -> Memory -> Hard Drive -> Format (or press Y button), enter the serial number of the machine to allow it to format (you find it on the back of the machine or in System -> System information)

Move the drive to the computer again, connect to sata, restore the partition 2 image with File -> Restore Partition 2 in Xplorer360 xtreme 2, select the XboxBackup.bin image created earlier. Update: It seems that partition 2 has to show up on xplorer360 before the restore function will work (it will not continue at Restoring Device). Either try to do a full restore or manually add the partition using the manual method below, only do step 1 under the Create Partition 0 section and step 4 under the Create Partition 2 section.

Drag all the files from the partition 3 file backup into partition 3 in Xplorer360 xtreme 2

Test drive in xbox 360, should show 107 GB total size and all the content should be restored successfully

Xplorer 360 full image backup method (alternate)

This method is essentially the same, the only difference is that a complete image backup of the drive is made and then restored. Partition 3 files are extracted from the image and then put back on the new hard drive.

Complete step 1 and 2 above under Original Xbox 360 drive to create hddss.bin of the original drive

Manual method

Complete step 1 and 2 under original drive and step 1 under new replacement drive in the XPLORER360 IMAGE AND FILE BACKUP METHOD section to backup the old drive and flash the new drive. Only when these steps are done, you can continue to create the partitions below.

Create Partition 0

If you want to use xplorer360 with the 120 WDBEVS drive, you can now do that:

1) First add the missing partition manually starting at byte 0x80000 of your WD BEVS. You need to make it look like:

58 54 41 46 00 00 00 00 00 00 00 10 00 00 00 01

So, the easy way to do this: open your drive with winhex( http://www.x-ways.net/winhex.zip, registration required to allow write changes disk ) by pressing F9, select your WD BEVS drive, press <ALT>+G, use position 80000 (hexadec) and then edit these 16 bytes starting at 0x80000 to look like above. Save it, restart the xplorer360 Beta 6 and the FATX error should be gone and you should see 2 partitions now. However, there'll be no data shown yet. if you are using a 120 gb version.

2) To get the data shown for an 120 gb wd BEVS you have to patch/hack xplorer360. Exit xplorer360 and fire up your hexeditor again, but this time open the xplorer360.exe itself with it. Make sure you're using the beta v6 version. At offset 0xF0C2 you'll find:

68 77 03

You need to change these 3 bytes into:

00 C2 1A

Save it (make a backup !), restart it and you can now see the contents of the WD BEVS 120 gb, at least I can.
BTW, this 'hack' won't work with the 20 gb version, so it's best to make a backup of the xplorer360.exe and use the 'unhacked' original version if you want to access a 20 gb hdd !

Create Partition 2

I did some analysis myself and got it working too Here's how I did it:

Save it and then your drive will show partition 2 in xplorer360! Dump all files from partition 2 from some HDD that has the emulator on it (either a 20 gb or 120 gb, doesn't matter), save those files from partition 2 to your PC. Attach your WD BEVS drive, and drag the 'index' file alone first to partition 2! After you've added this particular first file, you can add the rest to the partition.

After you've copied all files (you should be able to use all xplorer versions by the way, doesn't matter which one, hexedited/modded or not), your emulator should work.